Door-operating apparatus



B. T. GLOR Oct. 31, 1967 DOOR-OPERATING APPARATUS Filed Aug. 2l. 1964 INVENTOR jy/vga Z aaf;

Mm im ATTORNEYS United States Patent Ollice 3,349,559 Patented Oct. 31, 1967 3,349,559 DOOR-OPERATING APPARATUS Byron Thomas Gloor, Suhr, Aargau, Switzerland, assigner to Atlas'Kass'enfabrik A.G., Rupperswil, Switzerland FiledAllg. 21, 1964, Ser. No. 391,233 Claims priority, application Switzerland, Sept. 10, 1963,

2 Claims. (Cl. Y(S0-62.5)

t presenthautomatic door openers are generally controlled by carpets provided with electric contacts which are closed when the carpet is walked on. Such contact carpets are comparatively expensive and are furthermore subject to trouble through condensed water, dust and the like. Therefore it has been proposed to make use of switching systems controlled from a pneumatic carpet. Such switching systems, however, have not been able to establish themselves, because with them, for reasons explained more closely hereinafter, under certain circumstances, the doors closed involuntarily.

The object of the instant invention is to obviate this drawback, but the invention is not confined to the operating of door openers. I-t relates to `a switching system controlled from a pneumatic carpet, having piping leading to the pressure chamber of the pneumatic carpet and connected to a pneumatic switch and la member adapted to permit slow pressure-equalization between the pressure chamber and atmosphere.

This switchin-g system is characterized by the provision of a stop member in the run of the piping of the pressureequalizing member, and that this stop member, as the pneumatic switch responds to suddenly increased pressure in the pressure chamber of the carpet, is closed through this switch, and consequently stops the pressureequalizing. The stop member can be closed direct or indirect upon response of the pneumatic switch. It may namely be formed by an electrically-actuated valve closed together with the switch, or else by a valve which is mechanically, for instance kinematically, connected to a door opener and kept closed by the d-oor opener as long as the latter is energized through the pneumatic switch.

Besides for door openers, such a switching system may also be used for electric-light switches in corridors, for water-ushing in urinals -and for other purposes.

The only figure of the drawing shows diagrammatically one preferred form of embodiment of the invention.

A pneumatic carpet 1, which is placed in front of a door (not shown) includes in the usual manner rubber or plastic flexible tubing 2, that forms the pressure chamber of the carpet and is closed at one end, but connected at the other to thin piping 3. Piping 3 at one end has joined thereto piping 4 leading to a pneumatic switch 5, and at the other end piping 6 which, through an electrically-actuated valve 7 and a tine regulating valve 8, opens to free atmosphere.

The pneumatic switch comprises a pneumatic chamber 9 bounded by a diaphragm 10 which is connected mechanically to a movable contact 11 facing a stationary contact 12. Switch 5 lies in the run of an electric line leading from an input terminal 13 to an output terminal 14. The other input terminal 15 is connected direct to the other output terminal 16.

Valve 7 is connected to the lines leading to the output terminals 14, 16 so as to lie parallel to the output circuit. The input terminals 13, 15 are connected to the electric mains, the output terminals 14, 16, say, to a door opener. The terminals 13 and 15 represent the connection points to the power line, and the terminals 14 an'd 16 represent the connection points, on which the control-gears for opening the door or for performing a corresponding function are connected.

The described arrangement works as follows:

If somebody sets foot on the pneumatic carpet 1, its flexible tubing is compressed, the air compressed therein causing diaphragm 10 to bulge as shown chain-dotted at 10i. The movable contact 11 comes thus into position 11', i.e. pneumatic switch 5 is closed, whereby the output terminals 14, 16 on the one hand .and 'also the electricallyactuated valve 7 on the other hand are put under line voltage. By the exciting of valve 7 the pneumatic piping 6 is closed so that no air can escape to atmosphere through the line regulating valve 8.

By the exciting of the door opener the door is opened, in front of which the carpet 1 lies. If the person who has walked onto carpet 1 does not pass through the door at once, but remains standing on the carpet, the door remains open until the person leaves the carpet. Thus it cannot happen that the door swings to closed position suddenly, as is the case with prior art arrangements without electrically-actuated valve 7; this sudden closing is not only very annoying if the person wants to go through the door just at that moment, but may even cause injuries, especially to children. In the prior art arrangements namely when without the electrically-actuated Valve 7, some air will continuously escape through the fine regualting valve to atmosphere as long as the carpet 1 is loaded, so that finally the pressure in the pneumatic chamber 9 drops to such an extent as to cause switch 5 to open and to disconnect the door opener from the line voltage, thus causing closing of the door. But not only does the door close in the usual systems in an unexepected and undesired manner; for when the carpet is again unloaded, it takes a rather long time until the outside atmospheric pressure has iowed back into the partial vacuum in the carpet. This generally takes a few minutes, since the temperature-equalizing opening must in these cases be very small, so that during this time the carpet responds very badly, that is to say it does not react at all to small weights (-'for instance little children).

On the other hand, there should be a certain connection of exible tubing 2 to atmosphere, either through the tine regulating valve 8 or through an invariable small oriiice, because otherwise slow pressure fluctuations in tlexible tubing 2, as caused by changes in temperatures, may finally lead to unintentional response of pneumatic switch 5. In the instant invention these slow pressure `fluctuations are prevented as formerly by the fine regulating valve 8. The pressure-equalization is stopped by the electrically-actuated valve 7 only when sudden pressure rise caused by treading on the carpet has closed the pneumatic switch 5.

Thus in the instant invention all advantages of the control by means of a pneumatic carpet a-re retained, without having to put up with the explained disadvantage which so far has greatly limited the use of these carpets.

The expression pneumatic carpet is to be construed in the widest sense; especially the carpet may be very narrow, so that functionally it may, for instance, replace the usual contact thresholds in street signalling plants.

To simplify the arrangement shown, the tine regulating valve 8 may be replaced by .a stopper screwed into the electrically-actuated valve 7, in which stopper there is provided a tine bore of, say, 0.25 mm. in diameter, through which pressure-equalization takes place as long as the valve is open. Alternatively, instead of the valve 7, use could be made of a stop member which is controlled through a mechanical linkage by the door opener, and is closed when the door opener, excited by the closing of switch 11, has opened the door. Also in this case the door remains open until the user has again left the pnuematic carpet 1, because the closing of the stop member prevents pressure equalization and thus, with carpet loaded, switch 11 remains in the closed position.

It is understood that various changes and modifications may be made in the embodiment illustrated herein without 3 4 departing from the scope of the invention as defined in 2. Switching system according to claim 1, in which the the following claims. pressure equalizing member is in the form of a ine-regu- What I claim is: lating valve. 1. Switching system controlled by a pneumatic carpet, especially for automatic door openers, comprising a cham- 5- RferellCeS Cited ber having a pressure responsive diaphragm, piping lead- UNITED STATES PATENTS ing from the carpet to the chamber, a switch connected to the diaphragm and responsive to the pressure in the Illin ggg-ggf; chamber land piplng, a regulating valve 1n pipe connect1on 3,094,843 6/1963 Martin n 60-54-5 with the carpet and the chamber permitting slow pressure 10 equalization between said chamber and atmosphere, and solenoid valve means normally open .and connected in the EDGAR W' GEOGHEGAN Primary Examiner' piping between the regulating valve and the pressure ROBERT R. BUNEVICH, MARTIN P. SCHWADRON, chamber and closing by said switch in response to sud- Examiners den increased pressure in said chamber and piping. v 15 

1. SWITCHING SYSTEM CONTROLLED BY A PNEUMATIC CARPET, ESPECIALLY FOR AUTOMATIC DOOR OPENERS, COMPRISING A CHAMBER HAVING A PRESSURE RESPONSIVE DIAPRAGM, PIPING LEADING FROM THE CARPET TO THE CHAMBER, A SWITCH CONNECTED TO THE DIAPHRAGM AND RESPONSIVE TO THE PRESSURE IN THE CHAMBER AND PIPING, A REGULATING VALVE IN PIPE CONNECTION WITH THE CARPET AND THE CHAMBER PERMITTING SLOW PRESSURE EQUALIZATION BETWEEN SAID CHAMBER AND ATMOSPHERE, AND SOLENOID VALVE MEANS NORMALLY OPEN AND CONNECTED IN THE PIPING BETWEEN THE REGULATING VALVE AND THE PRESSURE CHAMBER AND CLOSING BY SAID SWITCH IN RESPONSE TO SUDDEN INCREASED PRESSURE IN SAID CHAMBER AND PIPING. 